Question

Scoateti factorul comun a.5+10+15+...+1000.b.11+22+33+...+7700.c.4+8+12+...+400.d.10+20+30+...+480.

Answer 1

a)5+10+15+...+1000=5(1+2+3+...+200)= 5×200×201/2= 5×100×201=500×201=100500

b)11+22+33+...+7700=11(1+2+3+....+700)=11×700×701/2=11×350×701=2698850

c)10+20+30+...+480=10(1+2+3+...+48)=10×48×49/2=5×48×49=11760

Answer 2

Răspuns:

E simplu

Explicație pas cu pas:

a) 5+10+15+...+1000=5•(1+2+3+...+200)

b) 11+22+33+...+7700= 11•(1+2+3+...+700)

c)10+20+30+...+480= 10•(1+2+3+...+48)

Cred că te descurci mai departe!